利用氢敏化处理的多模光纤制作了多模光纤光栅,并对多模光纤光栅的温度传感特性进行了实验研究与理论分析,表明这种光栅三个反射峰的布拉格波长随温度变化均呈现出良好的线性关系,并且重复性相当好,同一光栅的各反射峰的理论温度灵敏度系数都等于0.01 nm/℃,实验测得的温度灵敏度系数为0.0098 nm/℃或0.0099 nm/℃,与理论分析相当吻合,这些特性与单模光纤光栅的温度传感特性接近相同。因此可以用多模光纤光栅代替单模光纤光栅开发光纤光栅传感器,以降低成本;这一实验结果还可以作为对多模光纤光栅进一步深入研究的参考。

Fiber Bragg grating was written in hydrogenated multimode fiber, and the temperature sensing properties of multimode fiber gratings are investigated experimentally and theoretically in this paper. Experimental results show that the Bragg wavelength of grating in multimode graded-index fiber is linearly dependent on its temperature; and its repeatability is good. The measured temperature sensitivity of each reflection peak is equal to 0.0098 nm/℃; the temperature sensitivity attained from experimental data is tallies with theoretical analysis. The characteristics are similar to that of a conventional Bragg grating in single-mode fiber. So the multimode fiber grating may replace single-mode fiber grating to produce fiber sensors. The experimental results can also provide guidance for further studying on multimode fiber Bragg gratings.